Asphalt ultra-thin cover is a commonly used road maintenance technology.Although the open-graded asphalt ultra-thin wearing layer has good anti slip and drainage functions,its structure has a large porosity,which is prone to performance deficiencies and surface looseness,peeling and other diseases,limiting the application of open-graded asphalt ultra-thin cover.In order to improve the existing problems and shortcomings of open-graded asphalt mixtures and further promote and apply the ultra-thin cover of open-graded asphalt,this paper first prepared a high-performance epoxy asphalt,and then designed an open-graded epoxy asphalt ultra-thin cover with excellent comprehensive performance.Then,through indoor experiments,the basic road performance,surface anti slip performance,and The main research contents of surface anti loosening performance and interlayer bonding performance are as follows:Firstly,based on the optimization of the raw materials and preparation process for epoxy asphalt preparation,the composition ratio of curing agent to epoxy resin in the epoxy resin curing system and the composition ratio of epoxy resin to asphalt in the epoxy asphalt system were optimized through tensile tests.The optimal composition ratio of matrix asphalt,epoxy resin,curing agent,toughening agent,and diluent in the epoxy asphalt prepared in this paper was determined to be 3:1:1:0.05:0.08.Subsequently,viscosity tests,hydrophilicity tests,and fluorescence microscopy tests were conducted on the prepared epoxy asphalt;The viscosity test results indicate that the viscosity of the prepared epoxy asphalt increases with time and meets the specification requirements;The hydrophilicity test results indicate that the prepared epoxy asphalt has good water stability;The fluorescence microscopy test results prove from a microscopic perspective that the epoxy resin content in the prepared epoxy asphalt is reasonable.Secondly,an open-graded epoxy asphalt ultra-thin cover was designed using OGFC-10 grading.SBS modified asphalt,TPS modified asphalt,self-made HVA-I and HVA-II modified asphalt were selected as control groups,and the optimal asphalt dosage for the open-graded asphalt ultra-thin cover mixture was determined through Marshall testing.The basic road performance of open-graded epoxy asphalt ultra-thin cover mixture was compared and studied through indoor experiments.The test results showed that the high-temperature and water stability performance of the open-graded epoxy asphalt ultra-thin cover mixture was excellent,while the low-temperature performance was weak,but it could also meet the requirements of the specifications.The surface anti slip performance of OGFC-10,SMA-10,and AC-10 graded asphalt ultra-thin covers is compared and studied using manual sand laying method and pendulum friction meter method.The experimental results showed that the open-graded epoxy asphalt ultra-thin cover had good surface anti slip performance.A method for evaluating the looseness performance of asphalt mixtures based on twist testing was designed with the help of a self-made twist tester.Then,the surface anti looseness performance of five open-graded asphalt ultra-thin cover surfaces at different temperatures was compared and studied through twist testing.The experimental results showed that the open-graded epoxy asphalt ultra-thin cover mixture had the smallest loss of twist looseness mass at room temperature and high temperature,This indicates that epoxy asphalt can effectively improve the problem of loose and damaged surface of open graded asphalt ultra-thin cover.Finally,the interlayer adhesion performance of graded epoxy asphalt ultra-thin cover on cement pavement is studied through self-designed interlayer pull-out and shear tests.Composite modified emulsified asphalt,SBS modified emulsified asphalt and ordinary emulsified asphalt were selected as the bonding materials of ultra-thin cover.Through the interlaminar pull-out and shear tests,the optimal amount of three emulsified asphalt was determined to be 1.0kg/m2.The effects of test temperature and load loading rate on interlaminar pull-out and shear strength were studied.The test results showed that the interlaminar pull-out and shear strength decreased with the increase of test temperature,As the load loading rate increases,it increases.The interlaminar pull-out and shear strength of the three kinds of emulsified asphalt are all in the order of composite modified emulsified asphalt,SBS modified emulsified asphalt and ordinary emulsified asphalt from high to low,which indicates that when used as the bonding material of ultra-thin cover,the composite modified emulsified asphalt has more excellent interlaminar bonding effect than the other two kinds of emulsified asphalt. |